This application is related to my application Ser. No. 117,802 entitled Molded Self-Lubricating Split-Ring Bearing Assembly, U.S. Pat. No. 4,764,035, and to my application Ser. No. 92,657 which has now matured into U.S. Pat. No. 4,750,847, entitled L-Shaped Bearing Assembly, each of which show constructions related to those shown and claimed herein. As described therein, high speed relative movement between metal parts over prolonged periods create serious lubrication problems because bearings for such parts are produced from metals which have widely different coefficients of thermal expansion as compared to the rotating part. Such differences require good lubrication for they cause expansion at different rates which together with high relative speeds generate heat which collectively may cause undue wear and/or loss of lubrication, unless the seal between the parts is adequately forgiving and therefore can adjust thereto.
As described in the two above applications, which are hereby incorporated herein by reference thereto, entire supplies of lubricant may be lost as a result of such differences when previously known bearings are utilized. Materials with self-lubricating qualities such as Teflon, are very expensive, non-moldable, and therefore necessarily are machined, and consequently are relatively expensive to manufacture. Even such bearings often suffer relatively short lives, particularly when subjected to more than light pressures which may be created when a wide variety of physical conditions are encountered. Thus, there is a clear need for a relatively inexpensive bearing-seal designed to function adequately without excessive wear under high speed for extended periods, over a wide range of operating conditions and manufacturing tolerances. A dry bearing-seal, such as is disclosed herein, offers immeasurably greater advantages. The bearing-seal assemblies disclosed and claimed herein constitutes such an assembly.
The computer industry today has need for an effective bearing-seal to prevent air and foreign particles from passing from the motor into the disk drive area. In such applications, a shaft is mounted within a housing in very close proximity to each other, but yet in slightly spaced relation. The shaft is provided with conventional sealed bearings at each of its ends. Means must be provided between said ends to preclude such passage of air or foreign particles into the disk drive area. Such means is critical and must have a long life span if it is to satisfactorily meet commercial requirements. The bearing-seal described and claimed herein is particularly well-adapted for this purpose because it is a dry seal, requiring no lubrication and lasting much longer than bearing-seals heretofore known.